Fastener driving tools



Oct. 30, 1962 E. F. PFAFF ETAL. 3,060,440

FASTENER DRIVING TOOLS Filed Aug. 19, 1955 2 Sheets-Sheet 1 Oct. 30, 1962 E, F, PFAFF ETAL 3,060,440

FASTENER DRIVING TOOLS Filed Aug. 19, 1955 2 Sheets-Sheet 2 FIGA.

United States Patent Otiiee dbiglill Patented Get. 30, i962 3,660,440 FAS'IENER DRIVING TlLS Elmer 1F. Pfaff, Mantua, and Charles Il. De Caro, Cleveland, hio, assignors, by mesne assignments, to Olin Malthieson Chemical Corporation, a corporation of Viruned Ang. 19, 195s, ser. No. 529,454 11 claims. (ci. 1-4'7) This invention relates to tools for `driving nails, pins, studs and the like, and more particularly to a tool for holding and guiding a penetrating fastener while it is driven by another member, such as a hammer.

It will be understood that this type of tool generally comprises a tubular housing containing an axially-movable plunger or elongate anvil. The head of the fastener is guided within the bore of the housing, whereas the front of the housing is provided with supplemental guide means cooperable with the shank of the fastener. The principal problem with such a device occurs in connection with the front guide means, which should have a relatively close guiding cooperation with the shank of the fastener yet be adapted to pass the relatively enlarged head after the fastener is driven. In some such tools, the front guide prevents the head of the fastener from being driven down against the work, it then being necessary to complete the driving operation with a finishing punch after removal of the driving tool. In those cases where the head is driven against the work by the tool, the front guides must be transversely yieldable (so as to clear a path for the head), and for that reason may not provide sufficient guiding support. Accordingly, it is an object of the present invention to provide an improved tool whereby a headed fastener is precisely guided throughout the driving operation by a non-yielding front guide, which does not interfere with completion of the driving operation.

Among the several other objects of the invention may be noted the provision of a tool wherein the fastener may be driven to varying controlled depths; the provision of a tool adapted for use with threaded or other types of fasteners; the provision of a tool that applies compressive force to the work about the fastener while the fastener is driven, this being useful in certain applications, such as driving in plaster or concrete; the provision of a fastener and tool especially useful when it is necessary to drive an extra long or narrow fastener in materials likely to cause the fastener to buckle; the provision of a fastener and driving tool for use when the fastener is partially started; and the provision of a structure to be fastened with penetrating fasteners.

Briefly, the tool comprises a tubular housing having a front platen shaped to engage the work into which the fastener is driven. An elongate driver projects rearwardly from the housing, the driver being guided for axial movement from a retracted position to an advanced position wherein the front end of the driver is adjacent the front of the housing. The front of the tool is formed with an opening of sufficient size to admit both the shank and the head of the fastener, the head being guided by the driver or within a guide tube. The shank portion of the fastener is then guided by one or more apertured guiding elements releasabley held in the front or center of the tool.

Each guiding element may be and preferably is of an outer dimension greater than the fastener head but the inner opening should have a frictional press t with the shank of the fastener. The fastener and associated guiding element are then supplied to the user in assembly, the guiding element being seated on the shank well forward the head. This guiding element is to be distinguished from a conventional Washer in that it is a rigid non-yielding member that will positively prevent relative displacement of the fastener in the lateral direction and resist but permit relative movement in the axial direction. The outer dimension of the guiding element otherwise depends upon the character of the tool.

In a first disclosed embodiment of the invention, the tool is constituted by a housing and a one-piece driver, the bore of the housing having a telescoping cooperation with the guiding element assembled on the fastener. Where the guiding element is larger than the head of the fastener, as is preferred, the driver is recessed to` hold the head of the fastener. Accordingly, the shank is supported and guided at its head and by the guiding element Within the bore while the driver is driven forwardly.

In a preferred embodiment of the invention, there is a main driver section, a removable driver extension or drive rod, and a removable front guide tube all contained in a housing. The driver extension and front guide tube may be replaceable so as to accommodate fasteners of varying shape and size, and the bore within the guide tube has a close sliding cooperation with the head of the fastener. The front portion of the guide tube may then be counterbored or otherwise shaped to receive and hold the guiding element. For example, the front of the guide tube might be axially slotted and magnetized, or might be axially slotted and formed with a rearwardly-convergent counterbore, which develops a spring-wediging cooperation with the periphery of the guiding element.

Whereas the guiding element has the function of the front-guide means in prior nail-driving devices, it has other advantages also. Where the guiding element is disposed in substantial spaced relationship from both the penetrating end and the head of the fastener, the shank is less likely to bend or buckle. Indeed, several such guiding elements may be disposed in spaced relationship along the shank of an extra long or narrow fastener so that the fastener can be driven without risk of buckling. Furthermore, the fastener combination has particular utility in partial assemblies. For example, a strip to be nailed may have several penetrating fasteners in part imbedded at predetermined points and angles. This strip is then placed against a second member to which it is to be attached and the fasteners are driven home. When utilizing this invention, the fastener would be provided with guide elements disposed forwardly of their heads, so that a tool of the type disclosed can be utilized to insure that the fastener will be driven at the predetermined angles without damage to the strip or buckling of the fastener.

Other features of the invention will be in part apparent from and in part pointed out in the following detail description taken in connection with the accompanying drawings, in which:

FIG. 1 is an oblique view, parts being broken away to illustrate a first embodiment of the invention;

FIG. 2 is a longitudinal section of the tool shown in FIG. 1;

FIG. 3 is a View similar to that of FIG. 2, but showing an alternative embodiment of the invention;

FIG. 4 is a cross section taken on the line 4--4 of FIG. 3;

FIG. 5 is a view similar to that of FIG. 3 showing the driver in its retracted position;

FIG. 6 is a view similar to that of FIG. 3 showing a different driver extension and guide tube, such as would be used with a fastener or different size;

FIG. 7 is a detail view illustrating an alternative manner of holding the guide element of the fastener;

FIG. 8 is a sectional view showing another embodiment of the invention; and

FIG. 9 is a section taken on line 9-9 of FIG. 7.

Referring now to FIGS. l and 2 of the drawings, the

tool is shown to comprise a tubular housing 1 having a rear guard 3 and a forward platen 5. The guard 3 may be a collar threaded or otherwise secured to the housing, whereas the platen 5 is press fitted over `a tubular cap 7, which forms a 4tube extension reaching from the front of the housing to the surface of the work W, flush with the projecting tip of the fastener nose 27. In this illustrative embodiment, the cap slides over and is secured detachably to the housing by means of a screw 9. This cap is then formed with an opening 11 concentric with and of the same diameter as the bore 13 of the housing.

According to FIGURES 3-6, it is notable that the platen opening as shown at 311 may be of larger diameter than the fastener receiving bore and that the modified platen 105 is positioned with the aid of a tubular portion of the device extending rearwardly.

Otherwise, the housing opens rearwardly and contains an elongate driver 15, the rear portion of which projects from the housing and may be provided with a cap 17. The front portion of the drive rod is counterbored at 21 so as to hold the head 23 of a fastener F, the head being smaller than the bore 13. This head is necessarily larger than the main shank 25 of the fastener, and the front of the shank is provided with a penetrating nose 27. The head of the fastener is thus guided by the counterbored end portion 21 of the drive rod, whereas the shank of the fastener is guided by washer-like elements 19 and 29 fitted over the shank and vslidably received within the bore 13.

The center openings or apertures 31 -in the guiding elements 19 and 29 initially are slightly smaller than the shank of the fastener, so as to have a tight fit with the shank portion 25. It will be understood that the fastener would be initially delivered by the manufacturer with one or more guiding elements press fitted over the shank, the fit being such that `it would be impractical for the user of the tool to do this.

These washer-like guiding elements are further adapted to prevent buckling of the shank, should difiiculty be encountered in driving the fastener. In other words, the washers are designed to prevent any lateral displacement of the shank relative to the washer while permitting an axial displacement under the forces applied to the driver, as by a hammer. Consequently, washers formed of lead or soft plastic are not satisfactory, whereas steel washers would be satisfactory. The number and spacing of the guiding elements required will be determined by the character of the shank. If the shank is relatively short and strong, only one element adjacent the front may be sufficient, but if the fastener is unusually long or narrow, several such guiding elements will be desirable, as indicated in FIG. 2. The number and disposition of guiding elements will also be determined in some measure by the character of the work. For example, oak or metal structures offer considerable resistance to penetration. The maximum anti-buckling effect is achieved when the washer is disposed half way between the ends of the shank, although it may be desirable to move the washer forwardly somewhat in order to provide more positive guiding action during initial penetration of the work. In most instances, however, the guiding element will be spaced somewhat rearwardly from the tapering nose 27 in order to have a press fit with the shank.

The driver of the tool is movable to a predetermined retracted position. For example, the driver may be formed with a longitudinal groove 33, and the housing may be provided with a cap screw 35, the tip 37 of which seats within the groove 33. In its retracted position, as determined by engagement of the screw 35 with the front 39 of the groove, the front portion of the driver would be positioned back from the front of the housing a predetermined distance corresponding to the length of the fastener. Hence, when the fastener is inserted (the driver being in its predetermined retracted position), engagement of the fastener head 23 within the counterbore 21 limits rearward movement so that all guide elements are received within the barrel 13.

In operation, the tool is brought to bear against the work W so that the platen 5 is pressed against the work surface. The tapered nose of the fastener may be slightly pressed into the work or may be flush with the front of the platen, as illustrated. The fastener is then driven Iby striking the driver cap 17, as with a conventional hammer. As the anvil moves forwardly, the nose of the fastener is driven into the work W and the first retaining element is moved against the work surface. As the shank 25 of the fastener passes into the work, a frictional gripping effect is developed so that the guiding element is held in tight compressive relationship with respect to the work surface. This is advantageous in those applications where the work has a tendency to disintegrate or spall, the compressive force of the washer 19 tending to prevent such disintegration. When the fastener is fully driven, all washers are pressed together by head 25, which is in engagement with the back washer. The tool is then removed leaving the fastener and washers in place.

Referring now to FIGS. 3-6, a preferred second embodiment of the invention is `shown to comprise a tubular housing having `a rear hand guard 103 and a front platen somewhat similar to those described heretofore. It may be noted that both the hand guard 103 and platen 105 may be eccentric with respect to the tubular housing 101 so as to permit the tool to drive a fastener along side a projecting portion of the work.

In this embodiment, the housing is formed from an outer tube of rubber forming a hand grip and a metallic inner tube 102, to which the elements 103 and 105 are attached by any suitable means. A retainer spring 104 extends between the two sections of the housing, and this spring is provided with a detent 106 at its forward end. The retainer spring 104 is thereby sandwiched between the inner and outer tubes of the housing and releasably holds the two members in assembled relationship, there being an opening 108 in the inner tube cooperable with the detent 106 of the spring.

It is to be understood that any elastomer equivalent to rubber of suitable resilience for the purpose is contemplated for the outer tubular hand grip part of the housing and that by rubber is meant a vulcanized elastomer having stretch and snapback characteristics distinguishable from hard inelastic material (see Special Technical Publication No. 184, Committee D-20 on Plastics, of the Society for Testing Materials).

The driver, or driving plunger, is also of a two-piece construction, there being a back section telescoping within the inner `tube 102. A head 117 is provided on the rearwardly projecting portion of the driver, whereas the front end of section 115 is bored to accommodate a driver extension or drive rod 116. The rear portion of the driver extension seats within the tubular front of section 115 and is locked therein by means of a ball 118 seating within a peripheral groove 120.

As before, the driver is movable between advanced and retracted positions. A peripheral groove 122 is formed adjacent the tubular front of the back driver section 115 for cooperation with a rear detent 110 of the retainer spring 104, which projects through a corresponding opening in the inner tube to press against the outer cylindrical surface of the driver, thereby to releasably hold the driver in its retracted position. In its advanced position, the forward end 119 of the driver extension 116 or 216 is disposed adjacent the front platen 105, but the extension moves rearwardly to accommodate a fastener, as shown in FIGS. 5 and 6. In this embodiment, the head 123 of the fastener is then guided within a removable guide tube 121, which is releasably held within the front portion of the housing. The guide tube 121 may have peripheral grooves 135 cooperable with the spring detent 106. When the detent 106 is engaged in the back groove 135, the guide tube projects t from the front of the housing so that it can be gripped land pulled entirely from the housing against the resistance of the detent, this being desirable in order to permit replacement of the guide tube.

It is contemplated that there may be a selection of guide tubes and drive rods for handling fasteners of varying shape and size. The inner bore of the guide tube necessarily must vary, as shown at 113 and 213, with the diameter of the fastener head 123, hence the need for a replaceable guide tube where several different types of fasteners are to be driven. When the guide tube is changed, it will also be desirable to change the driver extension 116 to a corresponding diameter. Even when there is no change in the diameter of the extension, it may be desirable to change i-ts length, in order to vary the depth of penetration. For example, FIG. 6` illustrates how a somewhat shorter drive rod 216 would be used in driving a fastener where a substantial portion of the fastener is to project from the work, as is the case with a threaded stud. FIG. 6` also illustrates a somewhat larger bore 213 and corresponding increase in the diameter of the driver extension 216.

Returning to FIG. 5, the guide tube 121 may be moved to a retracted position wherein the detent 106 releasably engages within the front groove 135. It will be noted that the front portion of the guide tube is thus set back somewhat from the front of the tool, this being desirable in order to accommodate the entire fastener assembly. The fastener assembly includes a washer-like guiding element 129, as before, and in this embodiment, the guiding element is held in a counterbore 111 formed at the front of the guide tube rather than in the main bore 113. Normally, the guiding element will be set back somewhat from the front end of the fastener, and in order to hold the end of the fastener ush with the front f of the tool, the guide tube should be retracted, as illustrated in FIG. 5.

The fastener assembly is then held within the tool `by the guiding element. For example, the forward end of the guide tube may be slotted at 140 along opposite sides and then magnetized so as to achieve a horseshoe magnet effect. Necessarily, the surrounding portions of the housing be non-magnetic, so as not to bypass the magnetic field around the guiding element. Alternatively, as illustrated in FIG. 7, the tube may be slotted at 140 and the front counterbore 211 formed with a rearwardly convergent peripheral wall. With this arrangement, a wedging effect is achieved, the slots 140 serving to provide a spring bias for frictionally holding the washer within the tapering counterbore.

In the second embodiment of the invention, the guiding element need not have a press fit with the shank 12S, if such is not desired, in the absence of a tight frictional fit, the washer will be held in the counterbore until engaged by the head 123; At that time, the front of the back section 115 engages the back of the guide tube so that the fastener and guide tube move forwardly together to complete the driving operation.

Where the guiding element has a tight frictional engagement with the shank of the fastener, the initial blow may tend to move the washer from within the counterbore forwardly against the surface of the work, as the point of the fastener penetrates the work. In that event, the guiding element is primarily a centering device for insuring accurate alignment of the fastener shank preparatory to initial penetration. An anti-buckling action would be achieved, however, if the guiding element remained in the counterbore 111 as the fastener penetrated the work. For example, the guide tube 121 may initially so grip the retaining element that the entire tube will move forwardly against the resistance of the spring detent 106 during the initial penetration of the fastener.

FIG. 8 illustrates a further application of the invention. In some types of work it may be desirable to supply an item 201 which is to be fastened to another structure by one or more pre-set fasteners 203. In FIG. 8, this item is a laminated section of outer facings 205 secured to an inner wood core 207 with relatively small angled fasteners 209 in part projecting from one face. The assembly is then attached by the fastener 203, which is partly imbedded in that face. Such a strip might be used in laying wall to wall carpeting on a concrete floor, the item 201 being a strip secured to the tioor by the fastener 203 and the rug being held by the angled points of fasteners 209.

This fastener 203 has a head 223 and a shank 22S, the front or nose portion 227 of the fastener being imbedded. A guiding element 219 of the type described previously is temporarily secured over the shank part way between the head 223 and the work 201. A fastener driving tool of the general type described previously may be utilized to drive the fastener 203, the tool being aligned by telescoping cooperation with the head 223 and guiding element 219. As such, one or more fasteners may be pre-set at particular locations or angles to facilitate field operations, the guiding element insuring that the fastener is ultimately driven at the proper angle.

From the foregoing description, it is apparent that those skilled in the art will understand the structure, function and mode of operation of the invention herein disclosed, and appreciate the advantages thereof. Although several embodiments have been disclosed in details it is to be understood that the invention is not limited thereto, but the drawings and description thereof are to be understood as being merely illustrative. For example, al-

` though the specific disclosure contemplates -a tool used with an ordinary hammer, the invention would be applicable to air hammers or powder-actuated devices wherein the anvil is driven other than manually. It is realized that many modifications and variations will present themselves to those skilled in the art without departing from the spirit of this invention or the scope thereof as set forth in the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent it:

1. A hammer actuated tool for driving a fastener by hand into concrete, steel or the like, said tool comprising a hollow holder, an outer circumferential portion of which consists of a material adapted to be grasped in one hand, `an elongated fastener guiding element mounted at the front portion of said holder and having a bore for receiving said fastener, means at the front portion of said holder to retain said element relative to said holder in predetermined operable position, an elongated driving plunger slidably arranged within the rear portion of said holder and projecting rearwardly therefrom and having a separate drive rod coupled thereto and extending forwardly into said bore to engage said fastener emp-laced in said bore, said tool including yieldable means extending in said holder to retain said plunger in operable position with respect to said holder.

2. The tool of claim l wherein said yieldable retaining means includes a resilient member at least part of which disposed between said circumferential portion and plunger is urged to press against said plunger adjacent the rear portion of said housing.

3. The tool of claim 1 wherein said yieldable retaining means includes a resilient member, a part of which is urged to press against said plunger, and a circumferential groove in said plunger Ifor receiving said part of said member.

4. The tool of claim l including a laterally extending hand guard portion fixed at the rear end of said holder.

5. The tool of claim l wherein the rear portion of the holder adjacent the rearwardly projecting part of the plunger includes an extension forming a hand guard.

6. The tool of claim l wherein the material of said circumferential portion is an elastomer.

7. The tool of claim l wherein the coupling includes a detachable connection.

8. The tool of claim 7 wherein the connection comprises a circumferential groove on one of said plunger and rod and a member slidably mounted on the other in a radial passageway for extension into said groove.

9. A hammer actuated tool for hand driving into concrete, steel or the like a headed and pointed penetrating fastener having an elongated relatively slender shank terminating in an enlarged head of predetermined dimensions at the rear end and a tapering nose at the other end and with at least one washer slidably carried in presstted relationship on said fastener to gird said shank during driving rearwardly of the nose and forwardly of the head, said washer being of such rigidity and location as to prevent `buckling of said shank during driving, said tool comprising a tubular housing adapted to be hand held, an inner guide barrel at least most of which is adapted to be slidably telescoped within the front portion of the housing `for replaceable reception therein, an elongate driver received in telescoped slidable relationship for replaceable reception within the rear portion of the housing with a hammer impact receiving end projecting therefrom, said guide barrel having an axial bore of a size corresponding to said predetermined dimensions for receiving said fastener head in closely tting slidable relationship and sufficient to accommodate substantially the entire length of said fastener shank within said bore, and yieldable means in operative association with said barrel and driver for detachably retaining said barrel and driver in said respective housing portions at least with substantial frictional retention at operable positions therein, said driver having a replaceable forward extension of an outer diameter closely fitting the bore of the guide barrel for for striking said fastener head, said driver and extension being movable rearwardly at least to a retracted position such that substantially the entire length of the fastener and at least part of said extension are received within said bore preparatory to driving, thereby permitting replacement of both the guide tube and forward extension for accommodation of fasteners of various predetermined dimensions.

10. A hammer-actuated fastener driving tool for hand driving into concrete, steel or the like penetrating fasteners having an elongated relatively slender shank terminating in an enlarged head at the rear end and a tapering nose at the other end and at least one washer slidably girding said shank in press-fitted relationship rearwardly of the nose -and forwardly of the head, said fastener assembly including a washer adjacent said nose of said shank, said tool comprising a hollow open-ended holder adapted to be grasped in one hand, a replaceable fastener guiding element received within the forward portion of said holder, said guiding element having a bore for receiving a fastener, and a counterbore at the front end of said bore adapted to receive the foremost washer in laterally engaged forwardly releasable held relationship, a plunger telescoped slidably within the rear portion of said holder and projecting rearwardly therefrom `for receiving hammer impact, means for releasably holding said plunger within said holder, means for releasably holding said guiding element within said holder independently of the plunger holding means, and a replaceable drive rod mounted on said plunger to project forwardly therefrom within the bore of said guiding element for striking the head of said guided fastener, said releasable holding means being yieldable and disposed operatively between said rear portion and said plunger and between said front portion and said element respectively, said plunger and drive rod being not only progressible together whereby said drive rod is adapted to strike said fastener head while said plunger is in cooperative contiguity with said holding means but also completely retractible together by hand from said holder rearA portion and thereafter from each other, said element being retractable from said `front portion in opposition to each of said plunger and drive rod for replacement of each of said element and rod to accommodate fasteners of various sizes.

11. A hammer actuated tool for driving by hand into concrete, steel or the like surface a penetrating fastener having an elongated shank formed with a point at one end thereof and an enlarged head at the other end thereof and a washer press tted over the shank in spaced relationship from the ends thereof, said washer being of an outer diameter substantially greater than any other portion of the fastener and being formed of a material of sufficient rigidity so as to be adapted to substantially prevent lateral displacement of the shank relative to the washer, said driving tool having a holder formed with an elongate open-ended fastener guiding bore for admitting the fastener and washer thereon with a close slidable fit with said head, a driving member slidably contained within said bore at the back portion thereof for driving the fastener, the front portion of the bore being shaped to hold the washer in forwardly movable rearwardly constrained laterally-fixed relationship with respect to the bore and with said fastener protruding forwardly of said washer and holder, said tool bore and driving member being formed to hold the back of the fastener in centered forwardly movable, relationship with respect to the ybore of the tool, and said bore being largely of a relatively uniform diameter throughout its length ywith the front portion thereof being no smaller than the back portion, said tool including a platen mem- =ber mounted on a rearwardly extending tube means which is slidably mounted with respect to said holder, said platen extending from the front of said tube means at a right angle to said holder and forming a protective extension of said bore from said holder to said surface about the fastener protrusion and simultaneously forming means for positioning said received fastener substantially squarely to said surface and for resisting tilt therefrom.

References Cited in the le of this patent UNITED STATES PATENTS 952,571 Lamb Mar. 22, 1910 1,052,846 Price Feb. 11, 1913 11,141,073 Parks May 25, 1915 1,237,360 Martin Aug. 21, 1917 1,656,333 Lund Jan. 17, 1928 1,699,519 Brown Ian. 22, 1929 2,115,028 Logan Apr. 26, 1938 2,488,279 Fitzmaurice Nov. 15, 1949 2,543,942 Shaff Mar. 6, 1951 2,587,944 Williams Mar. 4, 1952 2,593,506 Wales Apr. 22, 1952 2,664,589 Szpilberg Jan. 5, 1954 2,666,201 Van Orden Ian. 19, 1954 2,676,508 Erickson Apr. 27, 1954 2,677,145 Adams May 4, 1954 2,705,323 Bossong Apr. 5, 1955 2,724,116 Termet Nov. 22, 1955 2,731,636 Bumiller Ian. 24, 1956 FOREIGN PATENTS 447,828 Germany Aug. 1, 1927 507,218 Great Britain June l2, 1939 826,409 France Mar. 3l, 1938 1,047,890 France July 29, 1953 1,062,838 France Dec. 9, 1953 1,100,553 France Sept. 21, 1955 

